AceShowbiz -

It looks like Liza Minnelli has fully recovered from a back surgery she underwent a few months ago. According to a new report from Page Six, the veteran singer returned to the stage earlier this week as she made a surprise appearance to support longtime friend Cortes Alexander at his annual holiday show.

She joined Alexander for a performance of "I Love a Violin". She then received a standing ovation from excited audience at Sterling's Upstairs at the Federal in Hollywood, which included Barbra Streisand's son Jason Gould and half-sister Roslyn Kind.

Minnelli had to undergo the surgery in September after she broke her lower back when picking up her dogs. "I broke my lower back. Remember a few years ago I was in a wheelchair because I had trouble with my spine? They operated on it then. Well, now, again. They'll have to fuse it," she explained. "I was picking up my dogs - and they jumped. And I got twisted and fell. I thought it's nothing. But it wasn't nothing. It became something. After an X-ray, seems I busted it and have to have it fused."

Minnelli is much better now. "She's feeling really good," a source told Page Six of the singer's current health condition.